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Date: Thu, 13 May 2021 21:31:16 +0200
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To: Larry Garfield <larry@garfieldtech.com>
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Subject: Re: [PHP-DEV] [RFC] Partial function application
From: andreas@dqxtech.net (Andreas Hennings)

On Sun, 25 Apr 2021 at 21:27, Larry Garfield <larry@garfieldtech.com> wrote=
:
>
> Greetings, Internalians!
>
> I would like to offer for your consideration another RFC, specifically sy=
ntax for partial function application.
>
> https://wiki.php.net/rfc/partial_function_application
>
> It includes an implementation by Joe Watkins that is already about 95% co=
mplete.  (There's some edge cases he's still sorting out, but all of the ty=
pical cases should work already.)  Most of the design work comes from Levi =
Morrison and Paul Crovella.  I helped out with the tests, a few edge bits, =
and general instigator/nudge. :-)
>
> Discuss.

This is super nice! I can imagine many ways I would use it.

Some questions / thoughts.

----

1. Serializing:

Will the partial function be serializable?
I assume if the original function is anonymous, then neither the
original nor the partial will be serializable.
Also if any of the fixed parameter values is not serializable, the
partial function can't be either.

But outside of the above cases it should be technically possible, or not?

----

2. var_export()

Calling var_export() on a partial function could produce the original
code that generated the function.
E.g.

var_export(foo(?), TRUE) =3D=3D=3D 'foo(?)'

-----

3. Parameter switching

Could we express the following as a partial function?

static function ($a, $b) {return foo($b, $a);}

E.g. as foo(?1, ?0) ?

Perhaps it doesn't need to be part of this RFC, but it is something to cons=
ider.

----

-- Andreas